Tying the shoelaces may be inconvenient. The traditional way of tying the shoelaces is mostly manual. However, it is inconvenient for people who cannot bend down and kneel down to tie shoes, and the shoelaces are often loose when walking and need to be re-tied. Therefore, it either takes extra time to tie the shoes or accidents might happen due to loose shoelaces. Thus, finding a way to automatically lace the shoes is desirable.
In the past decade, various methods tightening an article of footwear have been proposed.
US20080086911A1 discloses a weight-activated tying shoe wherein user who, upon sliding his foot inside the shoe, will depress a movable inner sole. This activates a side mechanism composed of a winch with a cable system used to close the tongue of the shoe towards the user's foot, thus lacing the shoe.
U.S. Pat. No. 5,117,567A discloses a shoe provided with a central closing device, especially a sport, leisure or rehabilitation shoe, with an upper formed of flexible upper materials, and with an instep shield which covers the instep. The instep shield is designed so that it can be fastened to the side parts of the shoe on both sides of the shoe upper, in a manner making is possible to tighten the instep shield and the side parts of the shoe upper over the entire closing area in a simple way and with as uniform a closing or tightening force as possible to guarantee as uniform a pressure distribution as possible along the entire throat area of the shoe.
U.S. Pat. No. 9,204,690B1 discloses a device for automatically tying and untying shoelaces. The device includes a gear box for positioning with the tongue of a shoe, the gear box having pulleys around which laces can be wound. A motor is included in the gear box for selectively turning the pulleys to wind and unwind the laces. Controls accessible via the tongue of a shoe are provided for activating the motor. The laces are included for winding through lace holes of the shoe and around the pulleys.
WO2016191123A1 teaches an article of footwear can include provisions for improving the operation and use of various systems associated with the article. The automated tensioning system may tighten and loosen the article of footwear through the operation of a motor. The automated tensioning system may also be able to store and recall a preset tension level.
However, the major shortcomings of these conventional shoe closure devices include large shoe size, noisy motor sounds, and poor maintainability, etc. In view of the disadvantages of the existing automatically shoe closure device, it is necessary to find a material, device or a combination thereof which is lighter, cheaper, and easy to handle. The objective of this invention is to provide a cost-effective and environmentally-friendly footwear system to realize an auto lacing function in the footwear by the virtue of the intrinsic shape fixing and shape recovery properties of shape memory polymers.